Standard Bank's Angolan unit was fined $800 by the central bank for foreign exchange violations but the South African lender said on Wednesday it had not breached any rules.

Angola's central bank said on Tuesday it will sanction seven financial institutions for failing to comply with foreign exchange rules, but did not elaborate.

"Standard Bank is of the view that it has not transgressed or misinterpreted the framework for implementation of foreign exchange resources and will defend its position," the bank said in an emailed response to questions by Reuters.

Angola's Banco Angolano de Investimento (BAI) said it was fined 683,222 kwanza ($4,139), while Banco Sol said it was asked to pay a 277,776 kwanza penalty.